The category of yellow G-type star includes as its most famous representative Sol, the original home star of terragenkind. These stars, which are located in the middle of the spectral sequence, are distinguished by very strong ionized calcium lines, with the hydrogen lines weaker. Metal lines especially iron become prominent. The statistics for G type stars are given below:

Spectral type

Luminosity - Sol = 1

temperature (Kelvin)

Mass - Sol = 1

Radius - Sol = 1

Density gm/cm3

G0

1.3

6,000

1.1

1.0

1.4

G2

1.0

5,800

1.0

1.0

1.4

G5

0.8

5,500

0.9

0.9

1.6

A G0 type star will spend about 8 billion years on the main sequence, the dimmer ones (G2, G5, etc) longer. These stars are excellent candidates for garden worlds, and life, when found, may be not only microbial but also include complex life-forms, rich ecologies, and even, on rare occasions, pre-sophont beings. Like solar systems of F type and K type stars, those of G-type stars are excellent for colonization, terraforming, and development. These stars are thus the prime real estate of the galaxy.

Spectral Class - Text by M. Alan KazlevA class to which a star belongs because of its spectrum, which in turn is determined by its temperature. The spectral classes are O, B, A, F, G, K, and M, from hottest to coolest.